A note on tropical rat mite (Ornithonyssus bacoti) infestation among workers in poultry farms of Namakkal, Tamil Nadu

An investigation was undertaken on layer chicken farms of Namakkal, Tamil Nadu to find out etiology for occurrence of skin lesions among the workers. It was found that, the incidence of allergic dermatitis among the workers was due to infestation with mites. However, the birds did not show any mite infestation during the time of examination and no production loss was reported. The samples of mites collected from the infested sheds were identified as Ornithonyssus bacoti. A drastic reduction in mite population was recorded following the application of cypermethrin (10%) at the concentration of 0.2% on the floor, cracks and cages for 3 consecutive weeks, along with wiping of pipelines with hot water.